KR20050028847A - Defect detector and defect detection method - Google Patents

Abstract

A defect detector and a defect detection method are provided to display a reference image which is compared with an image of a test board. An image display system and a maintaining element for maintaining a test object are provided. An image obtaining element picks up an image of the test object maintained by the maintaining element in order to obtain test image data(404) obtained by picking up an image of a defect region of the test object. The first display control element displays the test image data at the first display magnification on the image display system. The second display control element displays master image data(405) at the second display magnification on the image display system so that the master image data can be compared with the defect region, wherein the second display magnification is calculated in response to the first display magnification.

Description

DEFECT DETECTOR AND DEFECT DETECTION METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for inspecting a pattern such as a wiring pattern formed on an inspection object such as a printed circuit board, a film mask for creating a printed circuit board, or a glass mask. It's about technology.

Generally, a defect detector for detecting a defect such as a wiring pattern formed on the inspection object (hereinafter, referred to as a substrate) as described above has been proposed. The defect detector captures an image (hereinafter referred to as an "inspection image") of a defective portion (defective region) of the inspection substrate with an imaging device such as a CCD camera, and displays the image on the monitor. In addition, the defect detector similarly displays an image (hereinafter, referred to as a "master image") of the reference master substrate on the monitor. An operator of a conventional defect detector detects a defect of an inspection substrate based on an inspection image with reference to the master image displayed by the above-described method.

21 shows an example of image display on the display screen 100 of such a defect detector. Display areas 101 and 102 are set on the display screen 100, respectively. These display areas 101 and 102 display a master image and a display area 102, respectively. As shown in Fig. 21, in the conventional defect detector, the reference master image and the inspection image are respectively displayed so that the operator can visually detect the defect. Further, the defect detector displays the inspection image so that the operator can easily compare the two images with each other so that the display magnification is the same as the display magnification of the master image.

However, in the defect detection operation of the inspection substrate, the operator can operate the imaging device to change the display magnification of the inspection image. For the operator to make a fine comparison of the circuit pattern of the inspection image with the master image, for example, the operator enlarges the inspection image displayed in the display area 102.

22 shows an image (inspection image) displayed on the display area 102 enlarged by the operator's operation. In this case, since the conventional defect detector displays the master image and the inspection image at different display ratios, it is difficult to compare these images with each other and the working efficiency is disadvantageously lowered. Referring to FIG. 22, for example, the operator cannot determine whether the pattern 105 displayed in the display area 102 is to be compared with the pattern 103 or the pattern 104 displayed in the display area 101. .

In addition, when the defect detector can change the display magnification of the master image, the operator must change the display magnification of the master image minutely at the same time as the operation of changing the display magnification of the inspection image, which adversely reduces the work efficiency. .

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for inspecting a pattern such as a wiring pattern formed on an inspection object such as a printed circuit board, a film mask for creating a printed board or a glass mask, and more particularly, the present invention is compared with an image of an inspection substrate. A technique for displaying a reference image.

Therefore, the defect detector according to the preferred embodiment of the present invention is held by the holding element to acquire inspection image data by imaging an image display system, a holding element holding an inspection object, and a defective area of the inspection object having a defect. Answering an inspection image acquisition element for photographing the inspected inspection object, a first display control element for displaying inspection image data acquired by the image acquisition element on the image display system at a first display magnification, and a first display magnification; And a second display control element for displaying the master image data compared with the defect area on the image display system at a second display magnification calculated by the above.

Thus, the second display control element can display the master image data at any image magnification in accordance with the first display magnification.

Preferably, the defect detector is based on a size acquisition element for obtaining information indicating the size of the defect area for the inspection object held by the holding element, and based on the information indicating the size of the defect area obtained by the size acquisition element. And a display magnification control element for calculating the first display magnification according to the algorithm of.

Thus, the first display control element can automatically display the defective area at an appropriate magnification.

Preferably, the defect detection apparatus further includes an operation unit for receiving input information from an operator, wherein the second display control element sets a first display magnification whenever the first display magnification is set based on the input information. In response to the second display magnification, the master image data is displayed on the image display system at the second display magnification.

Therefore, it is possible to display the inspection image data at the display magnification requested by the operator and to change the display magnification for the master image data in response to the display magnification for the inspection image data.

The present invention also relates to a defect detection method for detecting a defect on the inspection object, which is obtained by imaging an inspection object held in a holding step and a holding step of holding an inspection object and imaging a defect area of the inspection object having a defect. An image acquisition step of acquiring inspection image data, a first display step of displaying the inspection image data acquired in the image acquisition step at a first display magnification on an image display system, and a second computed in response to the first display magnification And a second display step of displaying master image data on the image display system so as to be compared with a defective area at a display magnification.

Therefore, the master image data acquired at any image magnification can be displayed in response to the first display magnification.

Therefore, it is an object of the present invention to improve the working efficiency for the operation of detecting a defect.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the invention with reference to the accompanying drawings.

1 shows an example of the configuration of a defect detection system 1 including a defect detector 4 according to a first embodiment of the present invention. In the configuration of the defect detection system 1, the inspection apparatus 3 and the defect detector 4 are connected to each other via a network 2. The network 2 may be formed by an abnormal air line that is the same as that capable of data communication between the inspection apparatus 3 and the defect detector 4 via a local area network (LAN) or a predetermined communication protocol. In addition, a plurality of inspection apparatuses 3 and a defect detector 4 may be connected to the network 2.

2 is a block diagram showing the configuration of the inspection apparatus 3. The inspection apparatus 3 includes an operation unit 30 for inputting an operator's instruction, a display unit 31 for displaying operation information for the inspection apparatus 3, and an imaging unit for imaging the inspection surface of the substrate 90 to be inspected ( 32, a moving mechanism 33 for moving the imaging section 32 to a predetermined position, an image processing section 34 for processing image data captured by the imaging section 32, a network 2, and a control section 36. It includes a communication unit 35 for data communication between the inspection device 3 and the defect detector 4 through.

The operator operates the operation unit 30 to input an instruction to the inspection apparatus 3. Specifically, the operation unit 30 formed of various buttons, a keyboard, a mouse, or the like may alternatively be formed by a trackball, a joy stick, a touch panel, or the like. The display unit 31 formed by the liquid crystal monitor displaying various data may alternatively be formed by a light emitting diode (LED) or a display lamp.

The imaging unit 32 having the same function as a general CCD camera captures image data for each block in which the inspection surface of the substrate 90 is divided into predetermined sizes, and transfers the acquired image data to the image processing unit 34.

The moving mechanism 33 moves the imaging unit 32 to a predetermined position based on the control signal from the control unit 36. In addition, the moving mechanism 32 detects the position of the imaging unit 32 through a sensor such as an encoder and transmits it to the control unit 36.

The image processing unit 34 performs a predetermined image recognition process on the image data (image data of each block of the substrate 90) picked up by the imaging unit 32, and determines whether or not the substrate 90 has a defect. Decide

In addition, the image processing unit 34 generates the defect information 400 (FIG. 6) based on the detected position of the defect area and the size of the defect area, and transmits the defect information 400 to the control unit 36. The inspection apparatus 3 according to the first embodiment uses the center coordinates of the image data in which the defect region with respect to the substrate 90 is imaged and the center coordinates of the defect region in the image data as position information of the defect region. The vertical and horizontal dimensions of the defective area are used as the size information of the defective area. However, the positional information and the size information of the defective area are not limited to these. The inspection apparatus 3 may alternatively use the coordinates of the substrate 90 directly as information showing the position of the defective area, or use the number of pixels as information showing the size of the defective area, for example.

The communication unit 35 has a function of acquiring the defect information 400 generated by the image processing unit 34 through the control unit 36 and transmitting it to the defect detector 4 via the network 2. The control unit 36 composed of a CPU (not shown) and a storage device (not shown) controls other configurations of the inspection apparatus 3 by storing various data or executing calculations and generating control signals.

3 and 4 are front and side views of the defect detector 4, respectively. 5 is a block diagram showing the configuration of the defect detector 4. Figure 3 is defined by the horizontal XO axis and Y axis and the vertical ZO axis, Figure 4 is (1) X axis perpendicular to the Y axis and slightly inclined downward in the vertical plane from the horizontal XO axis, and (2) X axis And a Z axis orthogonal to the Y axis. The X and Z axes, which are oblique from the XO and ZO axes, respectively, may alternatively coincide with the XO and Z axes, respectively.

The defect detector 4 includes an operation unit 40 for inputting an instruction of an operator, a detection monitor 41 for displaying information and image data necessary for operating the defect detector 4, and a substrate 90. An imaging section 42 for imaging the defective portion as image data, an inspection stage 43 holding the substrate 90, a pair of horizontal moving mechanisms 44 arranged on both sides of the inspection stage 43, and an imaging section ( And a moving mechanism 45, a zoom mechanism 46, a communication unit 47, and a control unit 48 for moving the 42 in the Y-axis direction. The defect detector 4 also includes a support mount 490 having a cross-linked structure extending substantially horizontally between both sides of the inspection stage 43, and a support member for supporting the detection monitor 41 on the defect detector 4; 491 and a protective cover 492 for protecting the image capturing unit 42.

A defect detection system that performs inspection by comparing an image obtained by imaging the inspection substrate 90 with a master image (for example, image data obtained by photographing a master substrate as a reference, or digital bitmap image data created from CAD data). In 1), the operator uses the defect detector 4 as an apparatus for visually detecting the defect site as described later.

The operation unit 40 formed by various buttons, keyboards, mice, etc. may alternatively be formed by track balls, joysticks or touch panels. The operator can operate the imaging magnification by moving the dial or the like to directly drive the optical system of the imaging section 42. In this case, a dial or the like mounted on the zoom mechanism 46 corresponds to the operation unit 40. That is, the operation unit 40 can be formed by any mechanism as long as it is operated by an operator to input an instruction or the like in the defect detector 4.

The detection monitor 41 supported by the support member 491 on the defect detector 4 displays various data on the screen based on the control signal from the control unit 48. For example, a liquid crystal display or the like corresponds to the detection monitor 41. The defect detector 4 according to the first embodiment includes one detection monitor 41 corresponding to mainly one display device in the present invention.

The image capturing unit 42 is configured such that the optical unit (X-axis and Y-axis) of an optical system such as an image lens is actually provided through an image receiving element (CCD) having light incident therein along the optical axis () of an optical system such as an imaging lens. It is a general CCD camera which photoelectrically converts the light incident on the vertical axis), and image | photographs the board | substrate 90 (test object) hold | maintained at the test | inspection stage 43. FIG. The imaging unit 42 transfers the image data of the photographed substrate 90 to the control unit 48.

The upper surface of the inspection stage 43 is substantially parallel to the X-Y plane in order to hold the inspection substrate 90 transferred to a predetermined position by an operator or a conveying mechanism (not shown).

The moving mechanisms 44 mounted on both sides of the support stand 490 move the support stand 490 in the X-axis direction, respectively. Therefore, the controller 48 may control the movement amount and the position of the support stand 490. The moving mechanism 45 mounted on the support mount 490 moves the imaging section 42 along the support mount 490 in the Y-axis direction. Therefore, the controller 48 may control the movement amount and the position of the imaging unit 42.

For example, well-known mechanisms using a servo motor, a ball screw, and a transfer nut can be used as the moving mechanisms 44 and 45 having the above-described functions. The ball screw extends along a predetermined direction, and is rotated by the servo motor to move the feed nut in the predetermined direction so that the controller 48 can control the relative position by controlling the rotation angle of the servomotor. have. The moving mechanisms 44 and 45 are of course not limited to this and may alternatively be implemented by other well-known mechanisms.

Therefore, the defect detector 4 including the moving mechanisms 44 and 45 can move the imaging section 42 to any position on the XY plane. Therefore, the imaging part 42 can image the arbitrary area | region (the area | region which has a defect area | region) of the board | substrate 90 hold | maintained on the test | inspection stage 43. FIG.

Since the zoom mechanism 46 (not shown in FIGS. 3 and 4) has a function of determining the zoom position of the optical system of the imaging section 42 based on the control signal from the control section 48, the imaging section 42. ) Is determined. The zoom mechanism 46 may be operable directly from the operation unit 40.

The communication unit 47 communicates data between the defect detector 4 and the inspection apparatus 3 via the network 2. Therefore, the defect detector 4 receives the defect information 400 transmitted from the inspection apparatus 3.

As shown in FIG. 5, the controller 48 is connected to another configuration of the defect detector 4 in a state in which signals can be transmitted and received. The control unit 48 includes an instruction from an operator, a program for executing various operations via a CPU (not shown), and a storage unit for storing various acquired data, and forms a control signal to form another control unit of the defect detector 4. Each configuration is controlled.

Fig. 6 is a block diagram showing the functional configuration of the control unit 48 together with the flow of the signal. A CPU (not shown) of the control unit 48 is operated by a program so that a defective position and the like in the functional configuration shown in Fig. 6 are shown. The size calculating unit 481, the magnification calculating unit 482, the X / Y control unit 483, the zoom control unit 484, the inspection image display unit 485, and the master image display unit 486 are executed.

The defect position / size operation unit 481 including the magnification calculating unit 482 includes position data 402 showing the position of the defect area on the substrate 90 held by the inspection stage 43, and the display of the defect area. Display magnification data 403 showing magnification α1 is generated.

In order to generate the position data 402, the defect position / size calculation unit 481 is a position of a defect area included in the defect information 400 received in the communication unit 47 from the inspection apparatus 3 via the network 2. See information. The position data 402 includes a block number having a defective area (assuming that the surface of the substrate 90 is divided into blocks of a predetermined size, and the position of each block is set in advance according to the number). It includes the center position (X, Y) of the defect area.

The defect position / size operation unit 481 acquires the size (Xf, Yf) of the defect area from the defect information 400 and displays the size of the defect area from the display size data 401 (Xw, Yw) hereinafter. A " defect area display size " is obtained and transmitted to the magnification calculator 482. The defect position / size calculation unit 481 further generates display magnification data 403 based on the calculation result of the magnification calculation unit 482.

The magnification calculator 482 calculates the display magnification α1 of the defective area with respect to the defective area according to a predetermined algorithm based on the size of the defective area and the size of the defective area display, and returns the result of the calculation to the defect position / size calculation part 481. send. The initial value of the display size data 401 is set in advance.

The X / Y control unit 483 obtains the relative position between the imaging unit 42 and the defective area (substrate 90) based on the position data 402, and the imaging unit 42 is a position for imaging the defective area. It generates a control signal (pulse signal) necessary for moving to and controls the moving mechanisms 44 and 45. More specifically, the Y / X control unit 483 controls the moving mechanism 44 based on the block number and the value of X, and determines the position of the imaging unit 42 in the X-axis direction. The X / Y control unit 483 further controls the moving mechanism 45 based on the block number and the value of Y and determines the position of the imaging unit 42 in the Y-axis direction.

The zoom control unit 484 refers to the display magnification data 403 and calculates the imaging magnification β1 of the imaging unit 42 so as to image the substrate 90 inspected according to a predetermined calculation rule. The zoom control unit 484 further obtains an amount for driving the optical system of the imaging unit 42 in response to the acquired imaging magnification β1, and controls the zoom mechanism 46 to adjust the imaging magnification β1 of the imaging unit 42. Decide

Therefore, the defect detector 4 including the X / Y control unit 483 and the zoom control unit 484 detects the position and the imaging of the defect region captured according to the defect information 400 when the imaging unit 42 captures the defect region. Determine the magnification. Therefore, the defect detector 4 can acquire the inspection image data 404 of the defect area in accordance with the defect information 400 acquired by the communication unit 47.

The inspection image display unit 485 displays the inspection image data 404 on the detection monitor 41 after performing image processing necessary for the inspection image data 404.

The master image display unit 486 calculates the display magnification α2 for the master image data 405 compared with the defective area based on the display magnification data 403, and according to the obtained display magnification α2 for the master image data 405. The magnification γ 2 is adjusted and displayed on the detection monitor 41. That is, the master image display unit 486 mainly corresponds to the second display element in the present invention. It is also assumed that the master image data 405 obtained by imaging the entire area of the reference substrate at a predetermined imaging magnification β2 is acquired in advance and stored in the storage unit 480 of the control unit 48. The master image data 405 is preferably digital bitmap image data, more preferably binarized bitmap image data. The master image display unit 486 determines the displayed portion (not shown) of the master image data 405 by referring to the position data 402.

Referring back to FIG. 5, the support mount 490 extends substantially horizontally along the Y-axis direction from both sides of the inspection stage 43 to support the imaging unit 42 on the inspection stage 43. It has a crosslinked structure. The support mount 490 is provided with the above-described moving mechanism 45.

The protective cover 492 not only protects the imaging unit 42, but also prevents external incident light so that the imaging unit 42 can clearly capture the substrate 90. The protective cover 492 fixed to the support mount 490 is moved along the support mount 490 by the moving mechanism 44 to uniformly cover the upper portion of the imaging unit 42.

The defect detection system 1 has the structure and function mentioned above.

7 and 8 are flowcharts showing the operation of the defect detector 4 in the defect detection system 1. In the defect detection system 1, the inspection apparatus 3 extracts a defect area of the substrate 90 and generates defect information 400 prior to the operation of the defect detector 4.

The conveying apparatus (not shown) or the operator conveys the substrate 90 to be inspected to the defect detector 4 so that the inspection stage 43 of the defect detector 4 holds the substrate 90 at a predetermined position ( Step S11). The inspection apparatus 3 conveys the defect information 400 with respect to the board | substrate 90, and the defect detector 4 acquires the said defect information 400 through the communication part 47 (step S12).

Next, the control part 48 specifies the detected defect (defect area) of the board | substrate 90 (step S13). While the controller 48 specifies the defects in the order in which they are stored in the defect information 400 in the first embodiment, the operator can alternatively select the order.

When the control part 48 specifies the defect area to be detected, the detector 4 determines the position of the imaging part 42. (step S14). In step S14, first, the defect position / size calculation unit 481 generates the position data 402 for the defect area with reference to the defect information 400. Thereafter, the X / Y control unit 483 calculates the relative position between the substrate 90 and the imaging unit 42 on the basis of the position data 402, and finds a distance for moving the imaging unit 42. The X / Y control unit 483 also controls the moving mechanisms 44 and 45 to move the imaging unit 42 by the movement distance obtained first. Therefore, the defect detector 4 determines the position of the imaging section 42.

When the defect detector determines the position of the imaging section 42, the magnification calculating section 482 calculates the display magnification of the defective area (step S15). In step S15, the defect position / size calculation unit 481 first transmits the sizes Xf and Yf of the specific defect area with reference to the defect information 400. In addition, the defect position / size calculation unit 481 transfers the defect area display sizes Xw and Yw to the magnification calculation unit 482 with reference to the display size data 401. Thereafter, the magnification calculating unit 482 calculates the display magnification α1 for the defect area based on the size of the defect area and the size of the defect area display.

When the magnification calculator 482 calculates the display magnification α1 of the defective area, the magnification in the X direction and the magnification in the Y direction must be the same. In addition, it is preferable to indicate that the operator includes the entire defective area in order to detect the defective area at one time. Therefore, it is preferable not to enlarge the image data (inspection image data 404) obtained by imaging a defect area at the time of displaying a defect area. Therefore, in step S15, the magnification calculating unit 482 obtains the display magnification α1 for the defective area by the following expression (1).

α1 = min (Xw / Xf, Yw / Yf) (1)

Here, min (A, B) means the smaller one of A and B. The defect detector 4 is preliminarily provided with initial values of the defect area display sizes Xw and Yw, which are sizes that the operator can easily visually detect the defect area.

Therefore, the defect detector 4 in which the initial values of the defect area display sizes Xw and Yw are set can automatically calculate the display magnification α1 for the defect area. In addition, when the operator does not input an instruction, the defective area can be enlarged to an appropriate size and displayed regardless of the size (Xf, Yf) of the defective area.

When the magnification calculating unit 482 obtains the display magnification α1 for the defective area, the defect position / size calculation unit 481 makes the display magnification data 403 based on the display magnification α1 for the defective area obtained by the magnification calculating unit 482. Create

After that, the zoom control unit 484 and the zoom mechanism 46 determine the imaging magnification β1 of the imaging unit 42 (step S16). The display magnification α for the object is approximated according to the following equation (2) through the imaging magnification β and the magnification γ by image processing.

α = β × γ (2)

In step S16, the zoom control unit 484 refers to the display magnification data 403 and calculates the imaging magnification β1 of the image capturing unit 42 according to the following expression (3) according to the display magnification α1 of the defective area.

β1 = α1 (3)

According to the first embodiment, the zoom control unit 484 sets the display magnification α1 for the defective area to the imaging magnification β1 of the imaging unit 42. This means that in the formula (2), the magnification ratio γ = 1. Therefore, the defect detector 4 can display the defect area at the desired display magnification α1 obtained in advance without performing magnification conversion by image processing on the image data (inspected image data 404) obtained by the imaging unit 42. .

Thereafter, the zoom control unit 484 generates a control signal based on the obtained imaging magnification β1 and controls the zoom mechanism 46. Therefore, the zoom mechanism 46 drives the optical system of the imaging section 42 to change the imaging magnification of the imaging section 42 to the imaging magnification β1.

When the zoom control section 484 and the zoom mechanism 46 determine the position of the imaging section 42 and the imaging magnification, the defect detector 4 captures the substrate 90 with the imaging section 42 (step S17). . At this time, the controller 48 generates a shutter signal for the imaging unit 42 and outputs the shutter signal to the imaging unit 42. The imaging unit 42 transfers the image data as the inspection image data 404 to the control unit 48, which in turn is stored in the storage unit 480. The inspection image data 404 may be a still image or a moving image, a black and white image or a color image. That is, the inspection image data 404 can be any image as long as the operator can detect a defect in the circuit pattern.

When the imaging unit 42 generates the inspection image data 404, the inspection image display unit 485 executes the first display step (step S18). 9 and 10 show an example of the inspection image data 404 displayed in the first display step. In the first display step, the inspection image display unit 485 displays the inspection image data 404 on the display region 410 of the detection monitor 41 at the display magnification α1 of the defective region obtained in step S15. In the defect detector 4 according to the first embodiment, it is assumed that the imaging area of the imaging unit 42 is substantially the same as the display area 410. The size of the display area 410 (and the size of the imaging area) is larger than the defect display sizes Xw and Yw.

As described above, the defect detector 4 according to the first embodiment captures the imaging magnification of the inspection image data 404 by the formula (3) based on the display magnification α1 of the defect area (the imaging of the imaging section 42). Magnification β1) is obtained. Therefore, the operation of the inspection image display unit 485 for displaying the inspection image data 404 in the display area 410 of the detection monitor 41 at substantially the same magnification without performing the magnification conversion process is substantially performed. Corresponding to the inspection image display unit 485 for displaying the inspection image data 404 on the detection monitor 41 in accordance with the display magnification α1 with respect to the defective area determined by 482. That is, the inspection image display unit 485 mainly corresponds to the first display element in the present invention.

Therefore, the defect detector 4 which picks up the inspection image data 404 at the same imaging magnification β1 as the display magnification α1 in advance, does not execute the magnification conversion processing (e.g., digital zoom processing) by image processing or the like. Can be displayed. Therefore, the defect detector 4 can suppress the amount of calculation of the controller 48 in the first display step. If the imaging magnification for the inspection image data 404 is different from the display magnification α1 for the defective area, the inspection image display unit 485 refers to the inspection magnification data 403 for display on the detection monitor 41. Magnification conversion processing by image processing can be executed on the data 404. In this case, the defect detector 4 may display the inspection image data 404 at a magnification in which the zoom mechanism 46 is not provided.

In the manufacturing step of the substrate 90, defect areas of various sizes of the circuit pattern are formed on the substrate 90. However, the defect detector 4 calculates and displays the display magnification for the defect area according to the size of the defect area detected by the inspection apparatus 3. Therefore, the defect detector 4 detects the defective area at a size (Xw, Yw) that the operator can easily visually detect the defective area as shown in FIGS. 9 and 10 regardless of the size of the defective area. (41).

Thereafter, the master image display unit 486 executes a second display step (step S19). In the second display step, the master image display unit 486 displays the master image data 405 on the detection monitor 41 based on the display magnification α1 of the defective area obtained in step S15 while referring to the display magnification data 403. do. 11 and 12 show examples of screens displayed on the detection monitor 41 through the first display step and the second display step.

The master image display unit 486 obtains an enlargement ratio γ1 for displaying image data obtained at the imaging magnification β2 with the display magnification α1 according to the following equation (4). Accordingly, the master image display unit 486 determines whether to display the enlarged or enlarged master image data 405. Equation (4) corresponds to the equation obtained by substituting display magnification α1 and imaging magnification β2 into equation (2) and binomializing the term.

γ1 = α1 / β2 (4)

If the magnification γ1 is smaller than 1 in Equation (4), this means that the master image data 405 is reduced. On the other hand, if the magnification γ1 is greater than or equal to 1, this means that the master image data 405 is enlarged.

Therefore, according to the value of the magnification γ1, the master image display unit 486 obtains the magnification γ2 with respect to the master image data 405 by the following equations (5) and (6).

γ2 = γ1 (when γ1 <1) (5)

γ2 = lnteger (γ1) (When γ1 ≥ 1)

Here, Integer (N) represents the integer part of N. When the master image data 405 is enlarged, the enlargement ratio gamma 2 becomes an integer (natural number) from equation (6).

When the magnification γ2 of the master image data 405 is obtained, the master image display unit 486 substitutes these into Equation 2 to obtain a display magnification α2 for the master image data 405 to obtain an image necessary for the master image data 405. The process is performed and displayed on the display area 411 of the detection monitor 41.

α 2 = β 2 × γ 2 (7)

11 and 12, the master image data 405 is displayed along the display area 410 on the screen of the detection monitor 41 to simultaneously display the inspection image data 404 and the master image data 405. A display area 411 is provided, which is an area for displaying. In order for the detection monitor 41 to display the circuit patterns represented by the image data 404 and 405 in substantially the same size, the display magnification α1 and the display magnification α2 for the inspection image data 404 and the master image data 405 are actually The same value is given to each other.

As shown in Fig. 21, the conventional defect detector is also adapted to display the inspection image and the master image at substantially the same display magnification on the initial screen (the screen displaying the inspection image and the master image while not yet changed by the operator). It is composed. However, the conventional defect detector sets in advance the initial value of the imaging magnification for the inspection image and the enlargement ratio for each of the inspection image and the master image to display the initial screen. Therefore, the conventional defect detector cannot display the inspection image and the master image at the same display ratio even on the initial screen, unless the master image is obtained at a predetermined imaging magnification.

However, the defect detector 4 according to the first embodiment determines the display magnification α1 for the inspection image data 404 in order to display the defect area at a size easily detectable, and at the same time masters the display magnification α1. The display magnification α2 of the image data 405 is automatically determined. Therefore, the defect detector 4 can automatically display the master image data 405 obtained in advance at any imaging magnification at the display magnification substantially the same as that of the inspection image data 404. Therefore, the operator can easily compare the defect reference area and the defective area, respectively, without changing the display magnification α2 with respect to the master image data 405 manually and minutely. That is, the defect detector can streamline the operator's detection work. In the defect detector 4 according to the first embodiment, the display area 410 is said to be larger than the display area 411, but the display areas 410 and 411 may alternatively display images with the same size.

In the case where the master image data 405 is digital bitmap image data, the defect detector 4 does not perform interpolation between the pixels on the master image data 405 even if the master image is multiplied by an integral magnification. Data 405 can be displayed more accurately.

In order to enlarge the master image data 405, the defect detector 4 according to the first embodiment obtains an enlargement ratio γ2 through Equation (6). However, the method of calculating the magnification γ 2 to be an integer is not limited to this. For example, the defect detector 4 can alternatively obtain the magnification γ 2 by rounding off the first position of the decimal point of the magnification γ 1. When the master image data 405 is analog data or the defect detector 4 performs interpolation, the defect detector 4 can obtain the enlargement ratio γ2 through Equation 5 irrespective of the value of the enlargement ratio γ1.

When the second display step (step S19) ends, the defect detector 4 monitors whether the operator operates the operation unit 40 to input an instruction for changing the display size data 401 (step S21). Wait until the end of the detection operation relating to the defective area (step S28).

If the operator inputs an instruction to change the display magnification α1 during the detection operation on the defect area (Yes in step S21), the defect detector 4 receives the input information from the operation unit 40. (Step S22), in order to rewrite the display magnification data 403, a new display magnification α1 for the defective area is obtained (step S23). The term "input information" denotes the changed magnification αp requested by the operator for the currently displayed inspection image data. That is, the defect detector 4 obtains a new display magnification α1 for the defective area by αo for the defective area by the following expression (8).

α1 = αp × αo (8)

That is, the defect detector 4 rewrites the display magnification α1 for the defective area indicated by the display magnification data 403 to the value obtained by the formula (8) in step S23.

Thereafter, the zoom control unit 484 calculates a new image capture magnification β1 of the image capturing unit 42 based on the display magnification data 403 rewritten in step S23, controls the zoom mechanism 46 to control the image capturing unit 42. ) Is newly determined (step S24).

When the zoom control unit 484 determines the imaging magnification, the imaging unit 42 performs imaging of the substrate 90 to newly acquire the inspection image data 404 (step S25). In addition, the inspection image display unit 485 executes a first display step (step S26) to display the new inspection image data 404 in the display area 410 of the detection monitor 41.

At this time, the inspection image display unit 485 displays inspection image data 404 captured at the new display magnification α1 desired by the operator, similarly to step S18. Therefore, the defect detector 4 displays the defect area specified in step S13 at a new display magnification α1 desired by the operator.

When the master image display unit 485 displays the master image data 404, the master image display unit 486 executes a second display step (step S27) to display the master image data 405. FIG. At this time, the defect detector 4 calculates the display magnification α2 for the master image data 405 in the same manner as used in step S19 based on the display magnification data 403 rewritten in step S23.

FIG. 13 is a diagram showing an example of change of the display magnification α1 of the inspection image data 404 in the example shown in FIG. When replacing the inspection image data 404 displayed on the display area 410 shown in FIG. 11 with the inspection image data 404 displayed in the display area 410 shown in FIG. 13, the defect detector 4 Displays the master image data 405 on the display area 411 shown in FIG. 13 at a display magnification almost equal to that of the inspected image data 404 after the change.

That is, when the operator changes the display magnification α1 for the inspection image data 404, the defect detector 4 automatically converts the master image data 405 at the display magnification α2 according to the display magnification α1 for the inspection image data 404. To be displayed. Therefore, the operator can easily compare the image data 404 and 405 without performing an operation of changing the display magnification α2 with respect to the master image data 405 in order to improve the efficiency of the detection operation.

Referring again to FIG. 8, the controller 48 ends the detection operation on the defective area to confirm whether the operator has finished the detection operation on the entire defective area of the substrate 90 (Yes in step S28). )) Defect information is sent, and if another defect area exists, the process from step S13 is repeated.

If there are no other defective areas to be detected (Yes in step S29), the controller 48 determines whether or not another substrate to be inspected exists (step S30). The control part 48 repeats the process from step S11 if there exists another board | substrate to test, and complete | finishes a process if there is no other board | substrate to test | inspect.

As described above, the defect detector 4 according to the first embodiment displays the magnification of the master image data 405 to be compared with the defect area based on the display magnification α1 of the defect area determined by the magnification calculator 482. Calculate α2. The defect detector 4 displays the master image data 405 on the detection monitor 41 according to the display magnification α2 of the obtained master image data 405, and the arbitrary image magnification according to the display magnification α1 of the inspection image data 404. The master image data 405 captured at can be displayed. Therefore, the operator can easily compare the image data 404 and 405 with each other to improve the efficiency of the defect detection operation.

In the case where the operator changes the display magnification α1 for the inspection image data 404, the defect detector 4 also automatically changes the display magnification α2 for the master image data 405, whereby the conventional defect detector Alternatively, the operator can perform the detection operation on the master image data 405 without changing the display magnification finely. The efficiency of the defect detection operation can also be improved thereby.

In addition, the defect detector 4 simultaneously displays the inspection image data 404 and the master image data 405 on the detection monitor 41, whereby the operator can easily compare the defect area with the defect control area.

When the operator directly drives the optical navigation system of the imaging section 42 (which directly changes the imaging magnification β1), the defect detector 4 is configured to capture the imaging section 42 through the position of the optical system driven by the imaging section 42. The imaging magnification β1 is read, and the imaging magnification β1 is regarded as display magnification α1 through Equation (3). That is, the defect detector 4 can receive the display magnification α1 through this calculation. In this case, the zoom control unit 484 does not control the zoom mechanism 46, whereby the defect detector 4 may not newly obtain the imaging magnification β1 based on the received display magnification α1.

While the defect detector 4 according to the first embodiment displays the master image data 405 and the inspection image data 404 simultaneously, the display method of the image data 404 and 405 is not limited to this, and the defect detector is not limited thereto. (4) may alternatively display the image data 404, 405 in a switching manner.

Fig. 14 is a block diagram showing the functional configuration of the control unit 48 of the defect detector 4 according to the second preferred embodiment of the present invention constructed on the basis of the above-described principle together with the flow of data. The defect detector 4 according to the second embodiment differs from the defect detector 4 of the first embodiment in that it includes a switching unit 487 as a functional configuration of the control unit 48. The structures of the defect detector 4 according to the second embodiment are denoted by the same reference numerals for the components having functions similar to those of the defect detector 4 in the first embodiment, and redundant descriptions are appropriately omitted.

The switching unit 487 is configured from the operation unit 40 for switching display of the inspection image data 404 and the master image data 405 on the inspection image display unit 485 and the master image display unit 486 based on the input signal. Accept the input signal of.

15 and 16 are flowcharts showing the operation of the defect detector 4 according to the second embodiment. Steps S31 to S37 shown in FIG. 15 are similar processes to steps S11 to S17 shown in FIG. 7.

The defect detector executes step S38 for displaying the inspection image data 404 on the detection monitor 41 similarly to step S18 shown in FIG. 7 without performing processing corresponding to step S19. This is set so that the defect detector 4 according to the second embodiment displays the inspection image data 404 on the inspection image display unit 485 in the initial state, and the switching unit 487 receives no instruction from the operator. This is because the inspection image display unit 485 displays the inspection image data 404.

The operator can thus know that the imaging section 42 has picked up the substrate 90 and has visually detected the defective area.

Fig. 17 shows an example of the display made on the detection monitor 41 by the above-described method. As shown in Fig. 17, the display screen of the detection monitor 41 is switched to display only the inspection image data 404. Only the button 412 and the display area 410 are assigned. The function of the switch button 412 will be described later.

When the detection monitor 41 displays the inspection image data 404, the defect detector 4 according to the second embodiment determines whether or not an operator has made an input (step S41). This determination process corresponds to step S21.

In step S41, the defect detector 4 executes the processing (corresponding to the processing of steps S22 to S25 shown in Fig. 8) via the steps S42 to S45, if the determination is YES in step S41, while the determination is made. If this is NO, this processing is skipped.

Next, the switching unit 487 determines whether or not the switching button 412 is operated in accordance with an input signal from the operation unit 40, and determines whether or not to display the defect reference area (step S46). . That is, the switching button 412 has a function of inputting an instruction from the operator in the switching unit 487.

If the operator does not operate the switching button 412 (No in step S46), the switching unit 487 performs the first display step (step S47) to display the inspection image display unit 485. Corresponds to the process of step S26). If the defect detector 4 has already executed the processing in steps S42 to S45, the switching unit 487 calculates and displays the display magnification α1 for the inspection image data 404.

If the operator operates the switching button 412 (Yes in step S46), the switching unit 487 performs the second display step of step S48 (step S27) to display the master image display unit 486. Corresponds to the processing of.

18 shows an example of display made on the detection monitor 41 in the above-described manner. As shown in Fig. 18, the switching unit 487 can switch the display by the inspection image display unit 485 to the display by the master image display unit 486, and the display screen of the detection monitor 41 has a return button ( 413 and the display area 411 only. The return button 413 is used to return to the display by the inspection image display unit 485. That is, the defect detector 4 determines with Yes in step 46 if the return button 413 is not operated.

The processing of steps S49 to S51 executed after step S47 or step S48 is similar to the processing of steps S28 to S30 shown in FIG. 8.

As described above, the defect detector 4 according to the second embodiment can also obtain an effect similar to that of the defect detector 4 according to the first embodiment.

In addition, the defect detector 4 can effectively use the display area of the detection monitor 41 by switching the display by the inspection image display unit 485 and the display by the master image display unit 486.

Although the first and second embodiments have described the defect detector 4 displayed on one detection monitor 41, the method of displaying the image data 404 and 405 is not limited thereto, and the image data 404 and 405 are alternatives. Respectively may be displayed.

19 is a front view of a defect detector 5 according to a third preferred embodiment of the present invention constructed on the basis of the above-described principle. The defect detector 5 according to the third embodiment includes two detection monitors 414 and 415 as a display device for displaying various data on the screen. The defect detector 5 has substantially the same configuration as the defect detector 4 according to the first embodiment, except for the detection monitors 414 and 415, and the parts of the defect detector 4 according to the first embodiment. Portions of the defect detector 5 according to the third embodiment similar to are omitted from the description and appropriately indicated by the reference numerals shown in the first embodiment.

Detection monitors 414 and 415 having a function similar to the detection monitor 41 according to the first embodiment are arranged in the X-axis direction and are supported by the support member 491 as shown in FIG.

20 is a block diagram showing the functional configuration of the control unit 48 with the flow of data in the defect detector 5 according to the third embodiment. In the control unit 48 according to the third embodiment, the inspection image display unit 485 outputs to the detection monitor 415, while the master image display unit 486 outputs to the detection monitor 414.

The defect detector 5 according to the third embodiment is constituted by a device which performs a similar operation to the defect detector 4 according to the first embodiment shown in Figs. 7 and 8, while the inspection image display unit 485 Displays the inspection image data 404 on the detection monitor 415 in steps similar to steps S18 and S26. The master image display unit 486 also displays the master image data 405 on the detection monitor 414 in steps similar to steps S19 and S27.

Therefore, the defect detector 5 displays the defect area and the defect reference area on separate display devices so that an operator incorrectly acquires the inspection image data 404 for the master image data 405 or vice versa in the operation of detecting the defect. Try to avoid the possibility of making a mistake.

As described above, the defect detector 5 according to the third embodiment can also obtain an effect similar to that of the defect detector 4 according to the first embodiment described above.

Further, the operator may hardly confuse the inspection image data 404 with respect to the master image data 405 or vice versa in the operation of detecting a defect. Therefore, the defect detector gives the efficiency of the detection operation.

In each of the above-described preferred embodiments, the method of acquiring the defect information 400 is not limited to the use of the communication unit 47 via the network 2. The inspection apparatus 3 is alternatively portable for conveying the storage medium to the defect detectors 4 and 5 along the substrate 90 such that the defect detectors 4 and 5 read the defect information 400 from the recording medium. The defect information 400 can be recorded in a (portable) recording medium or the like.

The controller 48 executes the functional configuration by executing a program through software processing in each of the above-described preferred embodiments, while the controller 48 alternatively captures some or all of the functional configuration. This can be done by hardware processing via dedicated circuitry such as an axis control board.

The order of processing in the defect detectors 4 and 5 is not limited to that described for each of the above embodiments. For example, in step S14 the defect detector 4 according to the first embodiment can alternatively be configured to parallelize the processing, the same is true of steps S15 and S16, and the execution order of steps S18 and S19 can be reversed. Can be. That is, the defect detector 4 can execute the processing in any order as long as an effect similar to that described above can be obtained.

Although the operator inputs the changed magnification αp for the inspection image data 404 currently displayed in order to change the display magnification in each of the first to third embodiments, the input information is not limited to this. For example, the operator can alternatively input the desired new display magnification α1. Alternatively, the operator may input a new defect display size for rewriting the display size data 401 in order for the magnification calculator 482 to calculate the new display magnification α1.

While the defect detector 4 or 5 acquires the master image data 405 by imaging the substrate in advance and stores it or forms it from the CAD data, the operation may alternatively detect a defect area in real time. master image data 405 can be obtained in time. In this case, the defect detector 4 or 5 can set the imaging magnification β2 for the reference substrate along the display magnification α1 for the inspection image data 404.

While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. Therefore, it should be noted that many modifications and variations can be invented without departing from the scope of the present invention.

The present invention calculates the display magnification of the master image data to be compared with the defective area based on the display magnification of the defective area, and displays the master image data according to the obtained display magnification of the master image data. Images can be easily compared, and the work efficiency of the defect detection operation can be improved.

The inspection image data can be obtained at a desired magnification, the position of the imaging element is automatically determined according to the size of the defect area included in the defect information, and the display image data of the inspection image data is calculated to calculate the inspection image data. It can be displayed automatically at the appropriate display magnification. As a result, the inspection object can be picked up at the magnification to be displayed by the first display element, so that it is not necessary to adjust the magnification at the time of display, and the computation amount of the image processing can be suppressed.

By setting the display magnification of the master image data to be an integer multiple of the digital bitmap image data, it is possible to display highly accurate master image data, and display of inspection image data and display of the master image data are one of the display devices. The screen can be effectively used by simultaneously performing the comparison. The screen can be effectively used by alternately displaying the display of the inspection image data and the display of the master image data. Further, by displaying the first display element and the second display element on the display device, it is possible to prevent the operator from confusing the inspection image data with the master image data.

1 shows a configuration of a defect detection system including a defect detector according to a first preferred embodiment of the present invention.

2 is a block diagram showing the configuration of an inspection apparatus.

3 is a front view of the defect detector according to the first embodiment.

4 is a side view of the defect detector.

5 is a block diagram showing a configuration of a defect detector.

Fig. 6 is a block diagram showing the functional configuration of the control unit of the defect detector according to the first embodiment together with the flow of data.

7 and 8 are flowcharts showing the operation of the defect detector according to the first embodiment.

9 and 10 show display examples of inspection image data.

11 and 12 are diagrams showing an example of an image displayed during a detection operation in the defect detector according to the first embodiment.

FIG. 13 shows an example of change of display magnification with respect to inspection image data with reference to FIG.

 Fig. 14 is a block diagram showing the functional configuration of a control unit of the defect detector according to the second embodiment with the flow of data.

15 and 16 are flowcharts showing the operation of the defect detector according to the second embodiment.

17 is a diagram showing a display example of inspection image data in the defect detector according to the second embodiment.

18 is a diagram showing a display example of master image data according to the second embodiment.

Fig. 19 is a front view of a defect detector in accordance with a third embodiment of the present invention.

20 is a block diagram showing the functional configuration of a control unit according to the third embodiment with the flow of data.

21 is a diagram showing a display example of a master image and an inspection image in a conventional defect detector.

FIG. 22 shows a change example of the display magnification with respect to the inspection image shown in FIG. 21 in the conventional defect detector.

Claims (15)

A defect detector for detecting a defect on an inspection object, Image display system; A holding element for holding the inspection object; An image acquisition element for photographing the inspection object held by the holding element to obtain inspection image data obtained by imaging the defect area of the inspection object having a defect; A first display control element for displaying the inspection image data acquired by the annoying image acquisition element on the image display system at a first display magnification; And And a second display control element for displaying master image data on the image display system to be compared with the defect area at a second display magnification calculated in response to a first display magnification. The method of claim 1, A size obtaining element for obtaining information indicating the size of the defective area with respect to the inspection object held by the holding element; And And a display magnification control element for calculating a first display magnification according to a predetermined algorithm based on the information indicating the size of the defect area obtained by the size obtaining element. The method of claim 1, It further includes an operation unit for receiving input information from the operator, The second display control element calculates the second display magnification in response to setting the first display magnification whenever the first display magnification is set based on the input information, and calculates the master image data. 2. A defect detector for displaying on said image display system at a display magnification. The method of claim 1, And an imaging magnification determining element for determining an imaging magnification of the image acquisition element for imaging the inspection object according to a predetermined algorithm in response to the first display magnification. The method of claim 1, A position acquisition element for obtaining information indicating the position of the defect area with respect to the inspection object held by the holding element: And a placement element for determining a relative position of the inspection object held by the holding element and the image acquisition element in response to the information indicating the position of the defect area obtained by the position acquisition element. . The method of claim 1, The master image data is a digital bitmap image, And the second display magnification is a magnification value obtained by enlarging the digital bitmap image by an integer multiple. The method of claim 1, And a single display element included in the image display system simultaneously displays the inspection image data and the master image data by the first display control element and the second display control element, respectively. The method of claim 1, A switching element for displaying the inspection image data and the master image data in such a manner that the single display element included in the image display system is switched by the first display control element and the second display control element. Further comprising, a defect detector. The method of claim 1, The image display system, A first display element for displaying the inspection image data under control of the first display control element; And And a second display element for displaying the master image data under control of the second display control element. As a defect detection method for detecting a defect on an inspection object, A holding step of holding the inspection object; An image acquisition step of capturing the inspection object held in the holding step and acquiring inspection image data obtained by imaging a defect area of the inspection object having a defect; A first display step of displaying the inspection image data obtained in the image acquisition step on an image display system at a first display magnification; And And a second display step of displaying master image data on the image display system to be compared with the defect area at a second display magnification calculated in response to the first display magnification. The method of claim 10, A size obtaining step of obtaining information indicating the size of the defective area for the inspection object held in the holding step; And And a display magnification calculation step of calculating the first display magnification according to a predetermined algorithm based on the information indicating the size of the defect area obtained in the size obtaining step. The method of claim 10, And an operation step of receiving the input information from an operator to execute the second display step each time the first display magnification is set based on the input information. The method of claim 10, And an imaging magnification determining step of determining an imaging magnification for imaging the inspection object according to a predetermined algorithm in response to the first display magnification. The method of claim 10, A position acquiring step of acquiring information indicating a position of the defective area with respect to the inspection object held in the holding step; And And an arrangement step of determining a relative position between the inspection object held in the holding step and the imaging element for imaging the inspection object in response to the information indicating the position of the defective area obtained in the position acquisition step. , Fault detection method. The method of claim 10, The master image represents a digital bitmap image, And the second display magnification is calculated as a magnification value for enlarging the digital bitmap image by an integer multiple in the second display step.